LED Display

[Netvudu]

Hi there,

I´m creating a LED display, and I have several options. While I´m here working on it, I would like to check your ideas for the best approach to this.

I got two clear options in my head: one of them using an animated texture and the leds getting the color from it, and the other an animated geometry passing the color attribute to some points where the leds are copied, hence the leds getting the color as well.

for some reason I lean towards the second one, the geometry version if only because it would allow me to change stuff afterwards without recreating the animated texture, and trust me, they WILL ask me to change stuff.

Your thoughts?

[thinkinmonkey]

Hi Netvudu,

it seems an interesting project.

About methods you say, I'd prefer the first one, that with animated textures for three simple reasons:

1. Because a LED display has images on it and geometry of second method could not give so nice details

2. Because the client or anybody could give you the needed files for the final animation (avi, mov, tga...) or, in the worst case, he/she could ask you to help you animating the whole thing

3. Because in this case, I prefer not to animate geometry giving Houdini less headache, i.e. less CHOP, animated geometry, other nodes and so on.

[lisux]

Hi there,

I´m creating a LED display, and I have several options. While I´m here working on it, I would like to check your ideas for the best approach to this.

I got two clear options in my head: one of them using an animated texture and the leds getting the color from it, and the other an animated geometry passing the color attribute to some points where the leds are copied, hence the leds getting the color as well.

for some reason I lean towards the second one, the geometry version if only because it would allow me to change stuff afterwards without recreating the animated texture, and trust me, they WILL ask me to change stuff.

Your thoughts?

Is not possible to use just comp?

I mean project a texture over a card in Fusion or Nuke and then use masks to animate leds lights.

[Netvudu]

Thanks both.

thinkinmonkey, I appreciate your comments. Ironically I am almost finished prototyping the geometry version (yep,in 45 mins. Houdini rocks my socks) and it kinda works. I will probably try as well the texture version because attribute transfer is a bit of a hit-or-miss with distances, and even if it works, it´s not 100% perfect.

lisux, it is indeed possible to do this just in comp, but it was decided to make this in Houdini because after the LEDs show up several messages, some of them will start flying around (i.e. particles) and only a few of them will remain stuck, showing a final message. I already did one commercial for the same campaign (but not with LEDs) and they were quite picky with the whole particle fly around, so I really want to have a big control over how the LEDs will fly. I have done something similar in Fusion before and because of that I know the first part would be easier, but the fly-around part might be a bit more complex to control, specially if they end up asking for specific LEDs flying through specific areas of the screen.

[thinkinmonkey]

Netvudu,

then better for you!

Hoping to admire the final animation, I'll cross my fingers for you!

[jujoje]

Hey,

Not sure if this will be of any help, but created an asset a while back for creating leds. One of those things that I did since I figured it would come in handy as clients kept asking for leds. Never actually used it since the studio I work at went with xsi rather than houdini. So the assets non-commercial unfortunately, but might be of interest. And it'd be good to see someone get some use out of it :-D Oh and attached a render of one of the tests, as I had that sitting around too.

Think it should all be fairly self-explanitory, unfortunately rendering atm, so cant check whether I tidied the networks up of it's a flurb of nodes.

Hope it proves helpful in some way :-)

ns_led.otl

[edward]

So the assets non-commercial unfortunately, but might be of interest. And it'd be good to see someone get some use out of it :-D Oh and attached a render of one of the tests, as I had that sitting around too.

To encourage sharing, you can upload it to the Houdini Exchange.

[edward]

and it kinda works. I will probably try as well the texture version because attribute transfer is a bit of a hit-or-miss with distances, and even if it works, it´s not 100% perfect.

Hmm, I wouldn't do the geometry version using AttribTransfer. Can't you just construct procedurally in the first place? Barring that, I would probably just take some extruded text and just use the Group SOP w/Bounding Object option.

A fully functional 14 segment displays with automatic scrolling messages would make a nice odforce challenge. Something not too hard and fun?

[edward]

Feeble attempt using Group SOP attached

dotMatrix.hipnc

[Netvudu]

jujoje, thanks I will check this tomorrow (it´s too late right now)

edward, I´m not quite sure about constructing procedurally. It might work but I don´t visualize it that well in my head. I did try the Group SOP with bounding object a few hours ago, and it is working much better than the Attribute Transfer version, and it´s slightly faster as well.

[thinkinmonkey]

Edward: thanks for share. Could I ask you why have you used a DIVIDE SOP? Does it make the group's "bounding object" feature better and safe because there are more triangles?

Thanks.

[lisux]

It depends of the number of perticles or elements you have.

One option for me would be to get the inbetween technique.

Make your elemetns in 3D, explode them with your particles, and render an uv pass of them.

Map textures for the leds over the geo in any comp package.

I think this more flexible. You can even render masks from your 3D geo to animate your leds later in comp.

[edward]

Edward: thanks for share. Could I ask you why have you used a DIVIDE SOP? Does it make the group's "bounding object" feature better and safe because there are more triangles?

Yeah, it's probably not needed. I think the Bounding Object option might internally convert to triangles anyhow. I converted it to triangles just in case so that we won't have any non-planar polygons (not that I think the Font SOP will necessarily generate any).

[Netvudu]

Everything´s going ok with this project, but now I got another requirement and again I´m thinking on the best way to do this.

The LED screen has to fly away (particles)and I did this using a POPNet so that each LED square (primitive center)generates a particle, and then using a Primitive SOP to link the motion for each square with its respective particle. This worked great for each LED flying independently, but now they asked me to make squares of 9 LEDs flying together so that the pieces aren´t that small. A petition which frankly I saw coming because visually it makes sense.

The problem being I´m not sure how to keep the small primitive subdivision so that I can show text without huge pixelation, but still have bigger groups flying...any ideas?

Just like the last time I´m currently working on this (real-time message boarding! ), so feel free to post your "brainstormed" ideas while I try my own. I check every half an hour or so just in case anybody came with a cool way to do things.

If nobody replies I will still post the way I did it afterwards so that we can compare methods.

Edited July 15, 2010 by Netvudu

[lisux]

Well not sure what you mean by:

but now they asked me to make squares of 9 LEDs flying together

You mena you still need to have some leds invidually and other as bunch of nine forming a bigger square?

Or just use groups of nine as bigger squares and never use individual ones?

Anyway to move groups of nine, can you figure out any way to make you groups. Suppose you use and attribute and then use partition to get a sequence of groups like superLed_0, superLed_1, and so on ...

Then use a foreach to loop for every group, create a centroid for every one, so at te en od the for each you got one centroid point per super led (led formed by 9 leds).

Emit one particle per centroid point and do your amazing dynamics.

After this use another foreach to move every group based in the motion of evey particle, the number of particles and groups match!

If you have a light scene, with just the leds geo, or some of them grouped, send to me and I will try to make a fast example.

so far, this my "tempestad de ideas"

[Netvudu]

thanks bud.

I have light sample scene that you could use for showing me this wonderful method, much more elegant than what I was doing...

I will send it to your email asap.

[pencha]

I did that a year ago! Sadly I can´t find the file now.

I built a matrix of spheres, and with vopsops I transfered the R G and B values of a 1st proxy video separately to alternating sphere primitives.

A 2nd proxy video drove the effects on the LEDS (R values would trigger particle effects, G values would trigger DOPs, and B values would extrude the screen or something like that).

To make bigger chunks to fall I´d just use an expand filter on the G channel of the 2nd proxy video (the one controlling the effects).

Of course, the leds would start to fall in a bigger chunk, but they wouldn´t fall together till the end...

[Netvudu]

I finally achieved it (thanks to lisux) creating a bigger grid, then transferring the primitive index attribute from this bigger (i.e. less subdivided) grid to the more subdivided grid, so that several little LEDs would have the same primitive index attribute value and then using a ForEach to move each of those LEDs together.

Funnily enough, later on the client decided that he wanted to go back to the version in which each LED flew around single-handledly. Go figure...

[thinkinmonkey]

Clients!

[jkunz07]

Is not possible to use just comp?

I mean project a texture over a card in Fusion or Nuke and then use masks to animate leds lights.

I did this a while ago Nuke LED Script

Each display segment is a mask driven by a long if else if else etc. if I remember correctly.